Method of making piston-rod packings.



.1. E. MASTIN.

METHOD 0F MAKING PISTON ROD PACKINGS. 4 APPLICATION man DEC.7,1914.1,184,469, Patented May 23, 1916 z sHEETssHE-ET l.

C. l. E. MASTIN.

METHOD 0F MAKING PISTON ROD PACKINGS.

APPucATloN man DEc.7,1914.

` 1,184,469. Pmentd-May 23,1916.

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METHQD' 01E' MAKING PISTON-RGD IPACKNGS.

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Specification of LettcrsPatent.

Patented May 23, 19t@ application led December 7, 1914i. aerial No.875,795.

5 State of New Jersey, have invented certain new and useful improvementsin Methods of Making Piston-Rod' Packings, of which. the following is aspecification. i

This invention relates to a packing for piston rods and other movingparts of engines and machinery where a tight joint to prevent thepassage of steam, air, oil, or water is required; and also relates to anew method of making said packing. l

One of thciinain objects of the invention isfto provide a packing ofsimple construction which will be durable and yet yielding and elastic.

Another object of the invention isto provide a simple method ofconstructing the packing wherebyV it may be provided with alongitudinallyextendino rubber core having a longitudinally extendingaperture therethrough, whereby the packing will be elastic 'and willyield to the lateral vibrations of the piston rod or other moving part.

There are other objects and advantages of the invention, all of whichwill be fully hereinafter described.

In the drawings, Figurel is adetail perspective view of a portion of asheet or slab -of `packing material .before it is shaped to constitutethe outer shell of the packing; Fig. 2 a detail perspective view of theslab or sheet of packing material shaped to constitute the outer shellof the packing; F ig. 3 a similar view showing all of the parts of thepacking assembled and before i they are compressed to form the completepacking; Fi i a transverse sectional view ot' the comp ete packing stripafter 'it has been compressed and vulcanized; Fig. 5 adetail sectionalperspective View of the parts of the packing assembled and beforetbcyj'i-re compressed, vand showing a -i lling of asbestos; l'gfa-transverse sectional view'iii the complete packing strip made up aslshown in Fig. 5i; Fig. 7 a detail sectional perspective yview similarto lligs. 3 and 5, the llin'g block being provided with .softmetali'pliigls or studsg and Fig. 8 La trans veieersectional View othecomplete packing strip inade up as shown in. ik

In forming my packing l use a thin slab,

:idasV 1, "inade up ofalternate layers of fabric,

y such as'coinparatively' Yloosely woven cotton.

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duck, and interposed layers of rubber cement. This slab or sheet is cutof the proper Width and is then shaped or molded into channel form asshown at 2 in F ig. 2. This shaping mayv be done in any suitableinanner, preferably in a suitable mold, and while in the shaping mold itis subjected to sutilcient heat to partly vulcanize or cure it to holdit in its channel shape. A rubber tube 3 is placed in this channel, saidtube being of the desired thickness and of the desired diameter, andthrough this tube is placed a solid mandrel or rod 4c. In the `channelis also placed a filling block 5, the tube 3 and the block 5 beingarranged in the channel as illustrated in Fig. 3. The filling block 5,as

shown in Fig. 3, is made up of alternate layers of cotton duck andrubber, the said lay-i distort the rubber of the tube 8 to cause it tofill the space between the filling block and the walls of the channel.At the saine time the channel is contracted and condensed, as also arethe layers of cotton duck in the iilling block 5. Under this pressurethe packing is brought tothe condition shown in Fig. 4 wherein all theparts are brought closely together. While the assembled parts of thepacking are in this compressed condition they are subjected to heat at asuiiiciently high temperature to vulcanize or cure the rubber andthereby fix the packing p in the dimensions and in vthe condition towhich` it 1s brought by the pressure in the mold.; The lling block isforced into the4 channel" suliiciently to bring its outer surface flushwith the edges of the members 6 of the channel. It is to be noted thatthe edges of the duck layers in the members 6 in the filling blockappear on the surface 7 of the completed packing strip and said surfaceforms the Wearing face of the packing A which iii-adapted to be arrangednext to the piston rod or other moving part to be packed. The threads inthe layers of duck in the` slab 1 are on the bias, as are alsothethreads-inthelayers of duck in the lling block. Byreason of this theends only of y the fabric threads appear on' the Wearing surface and,therefore, all of the wear occastoned bythe inovingparts is directlyon-the ends of said threads. The rubber tube, after it hasbecome/incorporated in the completed packing, forms a rubber cushion 8,at the bottom of the channel and between said channel wallY and thefilling block, so that the filling block may have a slight inwardyielding inresponse to the lateral vibrations of the piston rod or othermoving part to be packed. The aperture 9 formed by the mandrel imaterially adds to the flexibility and resilience of the packing stripand also permits the packing to yield under the lateral vibrations of.the piston rod.

In Fig. 5 the falling block 10 is made up of asbestos fabricso that thelwearing surface 11 of the completed packing strip, as

shown in Fig. 6 is made up partly of asbestos and partlyof the layers ofrubber and cotton duck. This Aform of packing is especially adapted forcertain classes of machines and for Working under certain conditions. Inmaking up this' form of the packing a rubber tube 12 is placed in thechannel, as shown in Fig. v5, and through this tube is a ranged amandrel 13. WhenI the assembled parts of the packing are subjectfed topressure in a mold and to heat they Iare vulcanized and cured in onehomogeneous mass and form a complete one.

piece packing, as yshown in Fig. 6. f

In Fig. 7, a filling block 14 is shown made of alternate layers of duckand rubber with a central, longitudinally extending, thick rubbersection 15. In this rubber section oi' layer are inserted plugs 16 ofsoft metal, the ends of said plugs being flush with the Wearing surface17 of the/completed packing strip, as shown in Fig; 8.- In this form .oflling block the layers of cotton duck are parallel' with the layersl ofduck in the/ members 6. ofthe channel 2.' In this form of the packing atube 18 of rubber is placed in the channel precisely as described withrespect to Figs. 3 and 5. The assembled parts or sections of thepackingas shown in Fig 7 are subjected to pressure in a mold and to heat t0reducel the dimensions of the assembled' parts of'the strip and to cureor vulcanize them into one homogeneous mass, with the ends of the pins16 Hush with the wearing surface J17 of the packing method of assemblingthe parts and then compressing and curing them in their compressed'condition a packing strip having a longitudinally apertured rubber coreis produced in a very simple and inexpensive manner, and in which theedges of the fabric layers arev presented t'o the moving part to bepacked, and thev ends only of the threads in said fabric layers are incontact with said moving part.

The packing is first moldedin long strips, said strips being pressed andcured in a mold. This strip' may be coiled spirally if desired andsubjected to heat to preserve it in its spiral form. After the curingprocess,

lthe packing is lubricated in a suitable manchannel, and then subjectingthe compressed packing strip to heat, to vulcanize the rubber and topermanently unite all of the parts in one homogeneous mass.

In testimony whereof I hereunto affix my signature in the presence oftwo witnesses.

vCHARLES I. E. MASTIN.

Witnesses :v

F. It. MILLER, MINERVA VAN ALEN.

